I Learned From a Dime Store

Non-fiction by Helen Tozie

Dime for the Show

Non-fiction by Helen Tozie

The construction and evaluation of an achievement test in music for grade nine.

Thesis (Ed.M.)--Boston Universit

An Electrical-Type Indicating Fuel Flowmeter

An electrical-type meter has been developed for measuring mass rates of flow of gasoline or other nonconducting fluids. Its temperature dependence is small over a large range and it has no known vibrational or viscosity errors. The maximum temperature rise is less than 5 C. The rates of flow, measurable within 1% with the present instrument, are approximately 100 to 1,000 or more pounds of gasoline per hour when a potentiometer is used, or 100 to 300 pounds per hour when a deflection-type meter is used

Farewell

https://digitalcommons.library.umaine.edu/mmb-vp/3098/thumbnail.jp

Cathode Design for High Energy Molten Salt Lithium-Oxygen Batteries

State of the art commercial lithium ion batteries use cathodes such as lithium cobalt oxide which rely on insertion and removal of lithium ions from a host material. However, insertion cathode materials are limited in their capacity, and replacing them with a cathode that employs growth and dissolution of new phases could significantly increase a battery’s energy density. For example, oxygen and sulfur cathodes have been widely researched to this end, with both cases involving the growth of a lithium-rich compound on a current collector/catalyst support. We begin by describing the effect of using a molten salt electrolyte in a lithium-oxygen battery. In particular, we focus on how the electrochemical performance and discharge product, lithium peroxide, differ from that of a traditional organic electrolyte. In addition, we discuss the enhanced peroxide solubility in a molten salt and its implications for lithium peroxide growth and coulombic efficiency. Finally, we address the cell death of a galvanostatically cycled battery. We then introduce a similar phase-forming conversion chemistry, whereby a molten nitrate salt serves as both an active material and the electrolyte. Molten nitrate salts were previously studied as an active material in a primary lithium battery where lithium oxide irreversibly forms as nitrate reduces to nitrite. We will describe how the use of a nanoparticle heterogeneous catalyst allows the reversible growth and dissolution of micron-scale lithium oxide crystals in this system. After introducing these molten salt lithium batteries, we address the effect of cathode geometry on electrochemical performance. In particular, we note that the growth of such large, solid phase species on the surface of the catalyst support imposes new design restrictions when optimizing a cathode for energy density. As a proof of concept, we design and implement an architected electrode with large pore volume and relatively small surface area, comparing it with the more typical geometries of thin films and nanoparticles.</p

The Implications of Group Norms for Adaptation in Collectively Managed Agricultural Systems: Evidence From Sri Lankan Paddy Farmers

A growing literature seeks to explore the factors shaping adaptation to climate change. In collectively managed common pool resource systems, there is often a tension between behavior that benefits the individual and actions that benefit a larger group. Resource users in sustainable systems must therefore work together to ensure outcomes that are beneficial to the group as a whole. However, in the face of changing social, political, and environmental conditions, community norms may change, leading to the emerging of new behavioral patterns. Understanding when and why people decide to act in ways that benefit the group as a whole can help policy makers better target policies or change incentives to promote desired outcomes. This research seeks to build on research in common pool resource management and multilevel selection to understand how and why collective pressures shape individual adaptation behavior. Using qualitative data from in-depth interviews of farmers in Sri Lanka, this study confirms that collective management practices in Sri Lankan irrigation systems significantly influence farmer’s potential adaption behaviors. Based on farmer’s explanations of their own behavior, we hypothesize that farmer’s belief in the ecological necessity of cooperation and explicit government support for collective action are important drivers of collective action. Given the influence of community rules and norms, we conclude that efforts at adaptation are more likely to be successful if they target farmer organizations and communities as a whole rather than individual farmers